Logical flag for truncated distribution, stored as a logical
value. If IsTruncated equals 0,
the distribution is not truncated. If IsTruncated equals 1,
the distribution is truncated. This property is read-only.

Covariance matrix of the parameter estimates, stored as a p-by-p matrix,
where p is the number of parameters in the distribution.
The (i,j) element is the covariance
between the estimates of the ith parameter and
the jth parameter. The (i,i)
element is the estimated variance of the ith parameter.
If parameter i is fixed rather than estimated by
fitting the distribution to data, then the (i,i)
elements of the covariance matrix are 0. This property is read-only.

Logical flag for fixed parameters, stored as an array of logical
values. If 0, the corresponding parameter in the ParameterNames array
is not fixed. If 1, the corresponding parameter
in the ParameterNames array is fixed. This property
is read-only.